I've had a look at some of the videos posted and think I've identified your RDM, but not sure when looking at your stills. The time and order of the security vision jumps around so I've just described a simple chronological order.
Security Vison: JR and 3 friends exit Conti, talk on path outside for a short time. Red Dot Man exits. RDM (suddenly appears in JR and friends shot from a splice or different time jump) and shorter powerpole man (PPman) following him putting his jumper on, walks up to girls. RDM brushes past group possibly looking at JR, maybe making comment, seems familiar, definitely looks in her direction.
Girls go to Club Bay View but the line is too long and they decide to get a taxi and go home. JR declines to go with them and even when they drive past her in the taxi, she refuses lift.
Back on security camera, JR is back outside Conti and waits seemingly looking for a lift or person she may have made arrangements with. PPman is outside as well, seems to be keeping an eye on JR, shadowing her actions at times, or tries to look inconspicuous, alone holding one arm on a pole....(see description of a few extra frames from another video which seem to insert here)... Red Dot man exits Conti (this footage didnt show him going back in, but he must have when girls went to ClubBayView line). He brushes past JR standing by pole seeming to interact but doesnt stop. When he looks at camera his face is totally obscured by what looks to be an added block bar to the video clip and his face is invisible.
PPman stays where he is seemly keeping eye on JR.
Red Dot man who is now MM in widely recognisable stills comes into frame. JR seems delighted and interacts with a big smile. PPman turns his head away abruptly awkwardly looking over his shoulder directly away from MM and JR, while having one outstretched arm on PP. MM keeps on walking past JR.
Next shots with JR, waiting , looking at watch and going on road, PPman has gone. They make a big cut from 2.19 to 3.58 so you don't see when and where PPman goes. Commentator says JR then is gone from security vision two and a half minutes later.
RDM looked like MM who looks like BRE, IMO. If I have the wrong man for RDM, it looks to me it's MM. But in reply to noname, what about Adrian Bailey being PPman?
There were some extra frames from another video which adds to this scenario:
... MM sticks his head outside the door and looks left to right... gives sort of look to PPman who walks toward the Conti door straight after. Seems this fits just before MM comes out and brushes past JR waiting by pole.
Im interested in the couple of frames from inside the Conti from this video and have a still posted by Papertrail and Enzeder 11_09_2015 Thread #3 posts #4 and #15, which shows MM inside by stairs. Is anyone is able to make this image sharper?